Generally, a reinforced concrete (RC) construction, a steel-frame (S) construction, and a steel-framed reinforced concrete (SRC) construction are typically used to construct buildings. In recent years, as the buildings are large-sized and high-storied, a combination of three constructions has been widely used.
Furthermore, as the buildings are large-sized and high-storied, an earthquake-resistance and wind-resistance design becomes a major issue when constructing the buildings. Therefore, a core portion in which facilities such as an elevator, electric facility, system facility and a staircase are arranged is firstly constructed using the reinforced concrete construction, after which a main pillar portion for defining residence spaces is secondly constructed using the steel-frame construction.
FIGS. 1 and 2 show a conventional method for constructing a building having the SRC structure in which a core is constructed in advance.
In the drawings, the reference numeral 1 indicates a building core. The core 1 is constructed in advance using the RC construction considering the wind-resistance. Generally, a tower crane is installed in a core 1, and core dedicated facilities such as a hoist and a concrete distributor are installed an outer side of the core 1. A reinforcing bar 3 is arranged by the core-dedicated facilities, and a concrete 5 is applied to build the core in advance.
At this point, an anchor member 7 is installed when the concrete 5 is applied to prepare the construction of the steel-frame structure. The anchor member 7 includes a connecting member 7a buried in the concrete 5, an anchor plate 7b welded on the connecting member 7a, and a gusset plate 7c welded on the anchor plate 7b. 
After the above, a steel-frame beam 9 is assembled on the gusset plate 7c using high tension bolts 7c, after which a slab 11 is built by installing a slab type mold, arranging reinforcing bars and applying concrete to a slab mold.
However, in the conventional method for constructing a building using the SRC construction in which the core is firstly build in advance, many dedicated facilities such as the hoist and the concrete distributor are required to arrange the reinforcing bar and apply the concrete. The dedicated facilities should be removed for the construction of the slab, complicating the construction process and increasing the construction costs.
In addition, since the advanced core has a small size than that of the residence space defined by the slab, which will be constructed after the core, it is difficult to manage the manpower, manual tool and equipments. Furthermore, the core and the slab should be constructed by separately applying concrete, a reinforcing bar connecting the core to the slab have to be installed on walls in advance, thereby further increasing the construction costs. The separate application of the concrete is apt to deteriorate the quality of the buildings.
In addition, since the working processes for the core and the slab should be done remotely in a vertical direction, the construction process is complicated and the quality control is difficult.
Particularly, since there is no approaching path to the anchor member for installing the steel-frame, a safety rail should be installed on each of the members to install the steel-frame beam. As a result, the construction period is longer, and the construction costs are inevitably higher.